x11: Add necessary NULL check

diff --git a/gdk/x11/gdkdevicemanager-xi2.c b/gdk/x11/gdkdevicemanager-xi2.c
index 40e6aaa57819ec59b1cacfe1f6c925a2157680c5..851c52f0a3707fe676bdca1449476bc036442106 100644 (file)
--- a/gdk/x11/gdkdevicemanager-xi2.c
+++ b/gdk/x11/gdkdevicemanager-xi2.c
@@ -990,7 +990,8 @@ handle_property_change (GdkX11DeviceManagerXI2 *device_manager,
   device = g_hash_table_lookup (device_manager->id_table,
                                 GUINT_TO_POINTER (ev->deviceid));
 
-  if (ev->property == gdk_x11_get_xatom_by_name_for_display (gdk_device_get_display (device), "Wacom Serial IDs"))
+  if (device != NULL &&
+      ev->property == gdk_x11_get_xatom_by_name_for_display (gdk_device_get_display (device), "Wacom Serial IDs"))
     {
       GdkDeviceTool *tool = NULL;
       guint serial_id = 0, tool_id = 0;